Parse String to select certain variable

I am working on a inspector tool. I am wondering how can I pick/affect a variable in a object using a string (written variable name).

Example:

 public class Data {
    public int score;
 }
 
 public class Check {
    public Data data;
 
    public void Something() {
       Affect( data, "score", 10 );
    }
 
    public void Affect( Object obj, string variableName, ... ){
       //No idea what I should do
    }
 }

I am not exactly sure what I should search in Google at all. It will be greatly if someone can point me to the right direction/articles/webpage.